In a post on his Facebook page Friday, Zuckerberg gave an update on the company’s work toward his goal of addressing abuse from bad actors on the platform, a subject that gained prominence following revelations that Russians used the site in 2016 to push a disinformation campaign aimed at U.S. voters.

“We're a very different company today than we were in 2016, or even a year ago,” Zuckerberg wrote. “We've fundamentally altered our DNA to focus more on preventing harm in all our services, and we've systematically shifted a large portion of our company to work on preventing harm. We now have more than 30,000 people working on safety and invest billions of dollars in security yearly.”

But the anger from political leaders has not subsided. Instead, 2018 held even more scandals for Facebook revolving around its collection and handling of user data.

Facebook’s stock is down nearly 40 percent from its 2018 peak in July.

In March, it was revealed that Cambridge Analytica, a now-defunct conservative political firm, purchased data on millions of Facebook users without their knowledge from a researcher who had built a third-party Facebook app.

The scandal created a firestorm in Washington, where Zuckerberg was dragged before Congress for the first time in his career in a pair of heated hearings.

Zuckerberg on Friday said the company has been working for years to prevent such an incident from ever happening again and noted the company’s work to give users more control over their information.

“I've learned a lot from focusing on these issues and we still have a lot of work ahead. I'm proud of the progress we've made in 2018 and grateful to everyone who has helped us get here -- the teams inside Facebook, our partners and the independent researchers and everyone who has given us so much feedback,” he wrote. “I'm committed to continuing to make progress on these important issues as we enter the new year.”